A Belgian police officer secures the area around the European Council headquarters following last week bomb attacks in the Brussels metro and at Belgian international airport of Zaventem, in Brussels, Belgium, March 30, 2016. REUTERS/Yves Herman TPX IMAGES OF THE DAY

A Belgian police officer secures the area around the European Council headquarters following last week bomb attacks in the Brussels metro and at Belgian international airport of Zaventem, in Brussels, Belgium, March 30, 2016. REUTERS/Yves Herman TPX IMAGES OF THE DAY